Records of developed lots and wells in Okanogan County aren’t complete enough to determine where water is being used, but a new tool can help fill in the blanks.
Policy makers know how many lots existed before 1976, when the state rule governing water use in the Methow watershed was adopted, but not how many had houses. Records of building permits didn’t start until 1976 or 1977, said Bill Tackman, who’s been on the Methow watershed council for a decade. “It’s just a data gap we live with,” he said.
So the watershed council commissioned an update its 2011 water-tracking database. Completed in March, the database will help calculate how much water should be debited from the reserve the Methow Rule sets aside for the watershed, plus how much is left for new building (see story on page A1).
Having an accurate way to track water use could also provide ways to evaluate different types of use and project growth, according to Parker Wittman, director of professional services for Aspect Consulting, which produced the 2011 study and the new update in March.
Knowing how much a household uses would simplify the situation. “Once you get that number, it’s pure, simple math,” said Mike Fort, who was on the watershed council when it was formed and has since served 25 years.
The watershed council just wants data — it doesn’t intend to take a position on water allocations or whether to change the rule. “All we’re doing is counting,” said Tackman.
Improvements in county record-keeping over the past eight years allowed Aspect to refine the numbers in the dataset, according to Wittman.
Zoning changes account for a big drop in potential subdivisions. The new count found that if all land in the watershed was subdivided to the maximum allowed by zoning, there would be about 8,000 parcels — 24% less — than using the 2011 numbers.
Full buildout is an extreme case, said Wittman, who said the scenarios in the dataset for reduced growth are more realistic. “It’s important to keep in mind that buildout is not an estimate of actual growth — it’s a bookend of possible growth,” he said.
That maximum build-out varies by reach. In the Lower Methow, it went down significantly, but Aspect’s calculations show there’s a potential for more lots in other areas.
Based on state population projections, between 2011 and 2018, the dataset added 353 housing units in the entire Methow watershed, for a total of 5,299 (a 7% increase).
The idea of the database is to be flexible, to allow a user to compare different effects on water use — for example, by excluding conservation easements, national forests or group water systems, said Wittman.
Although the information in the database is now more accurate, it still needs to be “ground-truthed,” said Wittman. Some parcels are unbuildable because they’re in a wetland or on an overly steep slope, he said. The database can also be updated as new homes are built.
The database could be a useful tool for water tracking and planning, said Okanogan County Commissioner Andy Hover, who said it’s too early to know how the county might use it.
The county had started developing a system to track wells and water use, but it doesn’t have the flexibility of the Aspect database, said Hover. “There’s no sense in reinventing the wheel to track exempt [household] wells,” he said.
“We’re not only looking from the 2-cfs perspective, but also the comp plan — to see the total amount of water being used by permit-exempt wells,” said Hover. (The Methow Rule allocates 2 cubic feet per second to each of seven reaches in the watershed.)